We studied Mono Lake in my 6th grade class. It’s an interesting ecosystem because the lake doesn’t have any streams taking water away from the lake — it’s a dead end. Over the millennia the lake has gotten very salty, to the point where fish can’t live in it. But there are 2 varieties of algae, and they form the base of a somewhat small food web.
Back in 1913 the city of Los Angeles decided they needed the freshwater that was flowing into Mono Lake and others and built the largest gravity fed aqueduct to bring the water to LA. A lawsuit brought by the Mono Lake Committee managed to save Mono Lake, but not nearby Owens Lake, which dried up entirely. The agreement stipulated that LA would get 1/4 of the water going to the lake, and Mono Lake got the rest.
Now the Committee is trying to get LA to stop taking any water from the lake. We’ll see how this progresses.